You can get full control over how many radio items appear for a parameter and in how many columns (either by having all in a row horizontally, or all in a column vertically, or having a grid of them, ie. two columns with three choices in each etc..).
To do this:
1: Create a table on your custom panel.
Leave it as the default of 1 row and 1 column.
2: In the same UI select the 'Override Default' checkbox for 'Max Elements per row'.
Whatever number you put here will be how many column you have, so, if you want everything in 1 column vertically, put 1 here.
3: Add your parameter to the cell in your table.
(Remember that you created this table with only 1 cell, you DID not in step 2, change how how many cells you had).
When you add the parameter, make sure the checkbox for 'Extract Individual Controls' is selected.
You now have a UI element in a Custom panel that you can drag around, resize, etc.. and is completely configurable for how many columns and rows you want to display your radio buttons for.
Let me know if this gives you what you need!
Troy.
#DashBoard